To validate data unloaded using the COPY INTO <location> command, a Snowflake user can use the VALIDATION_MODE parameter within the SQL statement to test the files for errors without loading them3.

The Snowflake Cloud Services layer coordinates activities within the Snowflake account. It is responsible for tasks such as authentication, infrastructure management, metadata management, query parsing and optimization, and access control. References: Based on general cloud database architecture knowledge.

The list command in Snowflake is used to validate and display the list of files in a specified stage. When a user has unloaded data to a stage, running the list @file__stage command will show all the files that have been uploaded to that stage, allowing the user to verify the data that was unloaded.
References:
* Snowflake Documentation on Stages
* SnowPro Core Certification Study Guide